Taking daily selenium supplements may block the build up of HIV in a patient's blood, research suggests.

The University of Miami found a lower HIV viral load in patients who took selenium supplements for nine months.

Selenium deficiencies have been recorded in HIV patients, and evidence suggests the mineral can improve the function of the immune system.

The Archives of Internal Medicine study suggests the supplements may be a cheap and easy way to help keep HIV in check.

This research suggests that selenium supplements may be useful in addition to traditional combination therapy

Roger PebodyTerrence Higgins Trust

Advances in antiretroviral therapy (ART) have given HIV patients a longer life expectancy.

However, strict adherence to the therapy is required to keep HIV viral counts low, and there is a risk of side effects.

Therefore, scientists have been searching for alternative treatments to keep HIV under control.

More immune cells

Over nine months, the University of Miami team gave 91 HIV patients a daily capsule containing 200 micrograms of high-selenium yeast, and another 83 patients a daily placebo capsule.

The two groups had similar selenium levels at the beginning of the study, but after nine months levels were higher in the group taking the capsules containing the mineral.

Those with higher selenium levels in their blood were more likely to have a lower HIV viral load, and higher numbers of CD4 cells, which play a key role in fighting off infection.

The researchers said the exact mechanism by which selenium exerts its effects on HIV is not known.

One hypothesis is that selenium's antioxidant properties may repair damage done to immune cells by oxygen, which is produced at higher levels in the bodies of patients with HIV.

Writing in the journal, the researchers said: "Given the challenges of using conventional pharmacotherapy to achieve and maintain virologic suppression in HIV-spectrum disease, our results support the use of selenium as a simple, inexpensive and safe adjunct therapy."

Roger Pebody, of the HIV charity Terrence Higgins Trust, said: "We have known for some time that selenium plays a role in the immune system, but previous studies before combination therapy didn't show that these supplements have an impact on HIV.

"This research is more encouraging and suggests that selenium supplements may be useful in addition to traditional combination therapy.

"However, we wouldn't advise that people with HIV should rush out and buy these supplements immediately.

"Decisions on the value of taking supplements should always be made in consultation with your doctor."

Yusef Azad, director of the National Aids Trust, described the research as valuable.

"However, in interpreting this new report, it must be remembered that antiretroviral therapy is the only currently effective treatment for HIV.

"Selenium may have a supportive role alongside antiretroviral therapy but it cannot be a treatment in itself. "